     [:meta {:name "dtb:revisionDescription" :content revision_description}]
     [:meta {:name "dtb:totalTime" :content total_time}]
     [:meta {:name "dtb:audioFormat" :content audio_format}]]
-   (if library_number
-     (commercial-audiobook title creator language)
-     (default-book title creator))])
+   (cond
+     library_number (commercial-audiobook title creator language)
+     (= production_type "periodical") (periodical title creator)
+     :else (default-book title creator language))])
 
 (defn dtbook
   "Create a minimal DTBook XML template according to [the spec](http://www.daisy.org/z3986/2005/Z3986-2005.html) for a given `production`"


(defn default-book
  "Return an default book sexp"
  [title creator]
  [:book
   [:frontmatter
    [:doctitle title]
    [:docauthor creator]
    [:level1 [:p]]]
   [:bodymatter
    [:level1 [:h1] [:p]]]])


           source_date source_edition source_publisher source_rights source_title
           multimedia_type multimedia_content narrator produced_date
           revision revision_date revision_description
           total_time audio_format production_type
           library_number]}] ; only books imported from the libray have this
  [:dtbook {:xmlns "http://www.daisy.org/z3986/2005/dtbook/"
            :version "2005-3" :xml:lang language}
